1. Field of the Invention
This invention relates to omnidirectional positioning of vehicles.
2. Description of the Prior Art
The system for the movement of robots, forklift trucks, platforms, industrial and construction equipment, mobile chairs and a wide variety of other vehicles are continually being improved. There is particular need for improvements in systems which allow linear or curved movement in any direction from a point as well as rotation about a point.
In order to improve the movement, various systems have been developed which utilize rollers rotatably supported about the periphery of wheels. Such systems are shown in U.S. Pat. No. 3,746,112 to Ilon, U.S. Pat. No. 4,715,460 to Smith, U.S. Pat. No. 4,823,900 to Farnam and U.S. Pat. No. 5,186,270 to West. The U.S. Pat. No. 3,746,112 patent to Ilon discloses a four wheeled vehicle with each wheel having rollers supported about the periphery with the axes of rotation of the rollers on a wheel extending transversely to the axes of rotation of the rollers on the wheels on the opposite side of the vehicle and at the opposite end of the vehicle. This system is very maneuverable without the need to steer any of the wheels. However, depending upon the load, the contact pressure between each of the rollers and the surface can be very high, sometimes too high.